从python字典中的一组子键中查找最大值

Question

我有一个看起来像这样的列表（它是安然数据，因此是公开的，所以很确定我在这里没有违反任何规则）：

{
   'METTS MARK':{
      'salary':365788,
      'to_messages':807,
      'deferral_payments':'NaN',
      'total_payments':1061827,
      'loan_advances':'NaN',
      'bonus':600000,
      'email_address':'mark.metts@enron.com',
      'restricted_stock_deferred':'NaN',
      'deferred_income':'NaN',
      'total_stock_value':585062,
      'expenses':94299,
      'from_poi_to_this_person':38,
      'exercised_stock_options':'NaN',
      'from_messages':29,
      'other':1740,
      'from_this_person_to_poi':1,
      'poi':False,
      'long_term_incentive':'NaN',
      'shared_receipt_with_poi':702,
      'restricted_stock':585062,
      'director_fees':'NaN'
   },
   'BAXTER JOHN C':{
      'salary':267102,
      'to_messages':'NaN',
      'deferral_payments':1295738,
      'total_payments':5634343,
      'loan_advances':'NaN',
      'bonus':1200000,
      'email_address':'NaN',
      'restricted_stock_deferred':'NaN',
      'deferred_income':-1386055,
      'total_stock_value':10623258,
      'expenses':11200,
      'from_poi_to_this_person':'NaN',
      'exercised_stock_options':6680544,
      'from_messages':'NaN',
      'other':2660303,
      'from_this_person_to_poi':'NaN',
      'poi':False,
      'long_term_incentive':1586055,
      'shared_receipt_with_poi':'NaN',
      'restricted_stock':3942714,
      'director_fees':'NaN'
   },
   'ELLIOTT STEVEN':{
      'salary':170941,
      'to_messages':'NaN',
      'deferral_payments':'NaN',
      'total_payments':211725,
      'loan_advances':'NaN',
      'bonus':350000,
      'email_address':'steven.elliott@enron.com',
      'restricted_stock_deferred':'NaN',
      'deferred_income':-400729,
      'total_stock_value':6678735,
      'expenses':78552,
      'from_poi_to_this_person':'NaN',
      'exercised_stock_options':4890344,
      'from_messages':'NaN',
      'other':12961,
      'from_this_person_to_poi':'NaN',
      'poi':False,
      'long_term_incentive':'NaN',
      'shared_receipt_with_poi':'NaN',
      'restricted_stock':1788391,
      'director_fees':'NaN'
   }
}

我正在尝试列出所有exercised_stock_options 值，然后我想找到非NaN 值并执行最大值/最小值。

我这样做了，但我得到了一个不正确的答案，我不知道为什么：

eso = []
for k,v in data_dict.items():
    # name.append[str(k)]
    eso.append(v['exercised_stock_options'])

# Remove NaN values in list
eso = [x for x in eso if str(x) != 'NaN']

print(eso)

sorted(eso)
print(eso[0])
print(eso[-1])

但后来我看到了这个答案，它是正确的，但我看不出我做错了什么？

stock = []
for i in data_dict:
    if (data_dict[i]["exercised_stock_options"]=='NaN'):
        pass
    else:
        stock.append(float(data_dict[i]["exercised_stock_options"]))

ma = max(stock)
mi = min(stock)

print ("Exercised stock options maximum: ", ma, " minimum: ", mi)

Answer 1

在第一种情况下，值被排序为字符串，但是，您希望将它们排序为数字。这就是为什么在第二种情况下使用隐式类型转换（带有float 函数）的原因。

您可能希望将行 eso.append(v['exercised_stock_options']) 更改为 eso.append(float(v['exercised_stock_options']))。但你应该首先摆脱“NaN”值。